The invention relates to the evaluation, warning and treatment of neurological disorders such as epilepsy, devices for such evaluation, warning and treatment, including external and implantable devices and systems, and methods and techniques by which the devices and systems operate, and the methods by which patients suffering disorders such as epilepsy are evaluated, warned, and treated by electrical stimulation or some other modality. Specifically, the invention discloses a probabilistic approach for issuing warnings and/or triggering therapy delivery without relying on conventional event detection or prediction approaches. This may result in therapy delivery before the onset of a neurological event, such as seizure, or even before the onset of a pre-event state, thus preventing the neurological event from occurring.